Most umbrellas are constructed with a one piece stem as a superstructure with end pieces either swaged or threaded onto the stem. In other designs, the stem and end fitting is one piece with an integral eyelet and tip for the cloth attachment. The end tips in all of these designs are easily broken and difficult to repair or replace, thus, prematurely ending the useful life of the umbrella. The instant invention provides an improved means and an improved method for addressing these problems.
Typical prior art devices relating to umbrella construction are represented by the following prior U.S. patents which are of interest.
______________________________________ Patent Number Date Inventor ______________________________________ 4,089,416 March 22, 1977 Sims 1,381,350 June 14, 1921 Seery 1,336,218 April 6, 1920 Goldstein 1,264,076 April 23, 1918 Hout 777,999 December 20, 1904 Baldwin 297,281 April 22, 1884 Meyer ______________________________________
Sims discloses an umbrella tip repair kit which consists of a plastic tube and conical cap for use when the cover fabric has become loosened from the umbrella stem or rib. This repair kit device is not applicable for the repair of broken threaded end pieces or for original construction and therefore would not satisfy the intended function of the present invention.
Seery discloses a one piece umbrella stem with a rib swaged about the stem. This device was appropriate for original construction utilizing the fabrication techniques of the 1920's. It is not applicable to the hollow stem and threaded end piece construction which the present invention addresses.
Goldstein addresses a method of affixing the cloth cover of an umbrella to a hollow stem or rib by inserting an end pin into the hollow stem or rib and then capturing the cover between said end pin and a hollow tip which fits over said end pin. This device incorporates a two piece construction whereas the present invention accomplishes the same goal with a one piece end pin. In addition, the cover capture by Goldstein is less reliable than the cover-eyelet concept of the present invention.
Hout developed an umbrella attachment loop which consists of clips and twisted pins which form said loop and attach to a U shaped rib. This concept was directed to new construction and is not applicable to modern fabrication techniques for umbrellas.
Baldwin discloses a stem with integral eyelets which were designed to fit into a U shaped rib about the stem and eyelet and is not applicable to a hollow stem or rib as is the present invention.
Meyer also developed a stem and eyelet for a U shaped rib. These concepts do not pemit repair and replacement of the end pin and eyelet and therefore are subject to the problems that the present invention has been developed to address.
Existing umbrella designs fall into two major categories. In one style, the umbrella stems are of one piece construction and include integral eyelets for the cloth attachment. This design also includes an integral end tip. In the second style, the end tip is a separate piece from the stem. The separate end piece contains the cloth attachment location. The end piece is either swaged or threaded onto the stem. In some cases, a rib is placed around the stem or the stem is also referred to as the rib.
In both of these designs, the end tips or the cloth attachment eyelets are easily and often broken. Once this breakage occurs, the stem becomes a potential safety hazard. Repair or replacement of the end tip is very difficult and therefore the useful life of the umbrella is ended. Prior attempts to address end pin breakage have been awkward and generally ineffective.